Bone compression device

ABSTRACT

A bone compression device including first and second arms having respective first and second pins mounted thereon and projecting from one end thereof. First and second pairs of first and second couplings are rotatably mounted in spaced apart relationship on the respective arms. Externally threaded tightening rods screw through the respective first couplings and are rotatably connected with the second couplings whereby the pins may be engaged with bores formed in a fractured bone on opposite sides of a fracture and the rods rotated to draw the arms together and compress the fracture.

United States Patent m1 Halloran [4 1 Jan. 9, 1973 [54] BONE COMPRESSION DEVICE FOREIGN PATENTS OR APPLICATIONS [76] Inventor: William X. I-Ialloran, 440 Fair 1,206,411 8/1959 France ..129/92 A Drive, Costa Mesa, Calif 92626 1,507,627 11/1967 France ..l28/92 D [22] Flled: 1970 Primary Examiner-Richard A. Gaudet 21 N 93,173 Assistant Examiner-Ronald L. Frinks Attorney-aFulwider Patton Rieber Lee & Utecht Related US. Application Data [63] Continuation-in-part of Ser. No. 804,729, March 5, {57] ABSTRACT 1969, abandoned, which is a continuation-in-part of A bone compression device including first and second Ser. No. 737,688, June 17, I968, abandoned. arms having respective first and second pins mounted thereon and projecting from one end thereof. First [52] U.S.CI ..l28/92 A, 128/92 E n ec n pairs of first and second couplings are 51 Int. Cl. ..A61f 5/04 rotatably mounted in spaced apart relationship on the [581' Field 0: Search ..128/92 R, 92 A,92 D, 92 B, respective arms Externally threaded tightening rods 128/92 E, 92 Q, 83, 85 303 screw through the respective first couplings and are rotatably connected with the second couplings [56] References Cited whereby the pins may be engaged with bores formed in a fractured bone on opposite sides of a fracture and UNITED STATES PATENTS the rods rotated to draw the arms together and compress the fracture. 2,238,870 4/1941 Haynes ..l28/92 A v 2,251,209 7/1941 Stader ..128/92 A 10 Claims, 13 Drawing Figures PATENTEnJAx 91ers 3.709.219

sum 2 or 3 IN VENTOR. MLL/AM X. I144 Lam/v Mp.

BONE COMPRESSION DEVICE CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of U.S. application Ser. No. 804,729, filed Mar. 5, 1969 and now abandoned which, in turn, was a continuation-in-part of U.S. application Ser. No. 737,688 filed June 17, 1968 and now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for compressing a bone fracture either with or without a compression plate.

2. Description of the Prior Art Bone compression devices have been proposed which include a first arm which is engageable on one end with a bore drilled in a bone and a second arm which is engageable on its one end with a compression plate. Connecting means then connects such arms together and maintains them in parallel relationship and a tightening bolt is provided for drawing the arm together. A compression device of this type is shown in French Pat. No. 1,507,627. Devices of this type suffer the shortcoming that they cannot be utilized for external compression to compress a fracture without use of a compression plate and the arms cannot be adjusted to extend at an angle to one another for conveniently projecting pins mounted thereon through holes bored at an angle to one another in the fractured bone.

Joint compression devices have been proposed which include transverse pins that are projected entirely through the fractured bone on opposite sides of the fracture site to thereby project on their opposite extremities from opposite sides of the bone. Tightening buckles are then connected between the ends of the pins projecting'from the same side of the limb and such buckles tightened to draw the fractures together. A compression clamp of this type is sold under the trade name CHARNLEY ARTHRODESIS CLAMP by the Zimmer Corporation. Clamps of this type suffer the shortcomings that the pins must be projected entirely through the fractured bone to project from the opposite sides of the'limb thereby increasing the trauma and the likelihood of infection. Further, since tightening buckles are disposed on both sides of the limb, mobility of such limb is restricted thereby severely limiting the positions in which such limb may be placed for convenient access to the fracture sight by the surgeon. Additionally, such clamp cannot be used with a compression plate thereby making it necessary a hospital stock both clamps of this type and compression devices for use with compressionplates.

SUMMARY OF THE INVENTION The bone compression device of present invention is characterized bya pair of first and second arms including respective first and second pins projecting from their respective ends. Tightening means connects the two arms together and includes two pair of first and second couplings, with the first pair being pivotally mounted on the first arm in spaced apart relationship and the second pair being mounted on the second arm in spaced apart relationship. The first couplings are formed with bearing means and the second couplings are formed with threaded bores and a pair of externally threaded tightening rods screw through such bores and are rotatably connected with the bearing means whereby such rods may be rotated in one direction to move the arms apart and rotated in the opposite direction to draw such arms together.

An object of the present invention is to provide the bone compression device of the type described which may be utilized in an open reduction operation where a compression plate is secured over the fracture sight and also may be utilized in a closed reduction operation to compress the fracture sight.

Another object of the present invention is to provide a compression device of the type described wherein the arms may be disposed at different angles with respect to one another.

A further object of the present invention is to provide a bone compression device of the type described with may be disposed entirely on one side of a. fractured limb and need not project from the opposite side thereof.

A still further object of the present invention is to provide a bone compression device of the type described wherein the tightening means is spaced a substantial distance from the pin ends of the respective arms for convenient access by the surgeon for operation to draw such arms together to compress the fracture.

These and other objects and the advantages of the present invention will become apparent from a consideration of the following detailed description when taken in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a compression device embodying the present invention being utilized with a compression plate;

FIG. 2 is a vertical sectional view, in enlarged scale, taken along the line 22 of FIG. 1;

FIG. 3 is an elevational side view of a second embodiment of the bone compression device of present invention;

FIG. 4 is a horizontal sectional view, in enlarged scale, taken along the line 4--4 of FIG. 3;

FIG. 5 is an elevational sideview similar to FIG. 3;

FIG. 6 is a vertical sectional view taken along the line I 66 ofFIG. 5; I FIGS. 7 and 8 are perspective views of a third embodiment of the bone compression device of present invention;

FIG. 9 is a perspective view of a fracture which has been compressed by the bone compression device shown in FIG. 7 and the fractured limb then placed in a DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, the bone compression device of present invention includes a pair of elongated upstanding arms 65 and 67 which have respective pairs of first and second couplings 71 and 73, respectively, rotatably mounted thereon in spaced apart relationship. Threaded tightening rods, generally designated as 79, are screwed through threaded bores 81 in the second couplings 73 and project on their one ends into respective bores 83 in the couplings 71 and have mounted on their opposite ends enlarged finger-hold heads 85. The arms 65 and 67 have respective pins 91 and'93 projecting downwardly therefrom whereby such pins may be inserted in bores formed in a fractured bone on opposite sides of the fracture sight as shown in FIG. and the tightening rods 79 rotated to draw the bone segments together and compress the fracture sight.

The respective arms 65 and 67 each have vertically spaced apart bores 86 (FIG.12) drilled therethrough for receipt of reduced-in-diameter shanks formed by the respective couplings 71 and 73. Washers 87 overlie the ends of such shanks, project radially outwardly beyond the bores 86, and have retaining screws 88 projected therethrough and screwed into threaded bores formed in the shank of the respective couplings. Still referring to FIG. 12, the couplings 71 are formed with respective radially projecting blind bores 89 for receipt of one extremities of the respective rods 79. Securing screws 90 project through respective reduced-indiameter bores leading to the blind ends of such bores 89 and screw into respective threaded axial bores in the respective rods.79 to retain such rods in'rotatable engagement with the couplings 71. The arms 65 and 67 are conveniently made approximately five inches, long and the respective couplings 71 and 73 spaced apart a distance of three inches on each respective arm to thereby cause the compression device to project some distance from the bone which is being compressed for ment on one side of the fracture 104 by means of bone screws 105. A bore 106 may then be drilled in the other segment of the fractured bone for receipt of the pin 93. The pin 93 may be telescoped to project from the end of the arm 67 approximately l inch and the other pin 91 may be adjusted to project from the end of the arm 65 approximately a quarter of an inch. The locking levers 99 and 101 may then be tightened to hold the respective pins 91 and 93 in their respective telescoped positions. The bone engaging end of the pin 93 may then be inserted in the bore 106 and the plate engaging end of the other pin 91 engaged in an attachment slot 107 formed near the end of the compression plate 102 and the finger grasp heads 85 gripped to rotate the threaded rods 79 and draw the arms 65 and 67 together to thereby draw the bone segments together and compress the fracture site 104. It will be appreciated that the blunt, untapered bottom endof the pin 91 forms a straight longitudinal peripheral surface that enables such pin to remain firmly engaged with the abutment formedby the end of the compression plate attachment slot107 while the rods 79 are tightened to compress the fracture. The bone screw may then be inserted in a compression plate slot 107 not occupied by the pin 91 to hold the fracture 104 in compression. Thereafter, the tightening rods 79 may be rotated to take the tension off the arms 65 and 67 and the pins 91 and 93 retracted and a bone screw inserted in the remaining attachment slot 107. Thereafter, the incision may be closed and the patient will hopefully enjoy a rapid recovery.

The compression device shown in FIGS. 3-6 is substantially the same as that shown in FIG. 1 except thatit includes vertical tubes 105 and 107 mounted on the outside edges of the respective arms 65 and 67. The tubes 105 and 107 telescopically receive respective pins 111 and 113 which are held in place by adjustment levers 115 and 117. The rods 111 and 113 are V preferably formed with a series of peripheral corrugaconvenient operation and manipulation by the surgeon.

The respective arms 65 and 67 are formed with downwardly opening axial bores for telescopical receipt of respective pins 91 and 93 and respective transverse threaded bores are formed in the sides of such arms for receipt of the respective threaded shanks 95 and 97 of respective locking levers 99 and 101 which may be screwed inwardly to grip the respective pins 91 and 93 and hold them locked in their telescoped position. A particularly important feature of the bone compression device of present invention is that it may be utilized in an open reduction operation wherein a compression plate 102 is secured to a fractured long bone 103 to compress the fracture site 104 andmay also be utilized in a closed reduction operation as described hereinbelow.

In operation, when used in a open reduction operation to install a compression plate 102, the fracture site is located by taking an X-ray and an incision is made and the bone 103 stripped for receipt of such compression plate. A particular advantage of the compression device of present invention is that the pin 91 may be removed and replaced by a different sized pin for use with a different sized compression plate. The compression plate 102 is secured on one end to the bone fragtions 121 (FIG. 11) which bite into the cortex of the bone and prevent slippage therefrom.

In operation the bone compression device shown in FIGS. 3-6 maybe utilized with a compression plate as described hereinabove or may be utilized in an open reduction but without use of a compression plate. When utilized in an open reduction operation without benefit of a compression plate a longitudinal incision 122 may be made on top of the bone 124as shown in FIG. 3 and transverse bores drilled in such bone .on opposite sides of the fracture site 131 for receipt of the respective pins 1 11 and 1 l3.-It is particularly beneficial that the bores for receipt of the pins 111 and 113 may be drilled at an angle to one another and that the arms 65 and 67 may then be adjusted to dispose the pins 11 1 and 113 at corresponding angles for convenient receipt in such bores thereby doing away with the necessity of drilling such bores exactly parallel to one another. As shown in FIG. 3 the bores are drilled entirely through the bone and the pins 111 and 113 project entirely through such bone to thereby engage the relatively hard cortex on both sides of such bone to enable such bone to withstand relatively great amount of compressplitting such bone.

The adjustment levers 115 and 117 may then be loosened and the arms 65 and 67 raised on the pins 111 and 113 to the position in FIG. 5 to raise the lower end of such arms entirely out of the incision 122 so such incision may be closed. A cast 135 may then be applied to the exterior 133 of the limb to hold the bone segments on opposite sides of the fracture 131 in axial alignment and also hold the pins 111 and 113 securely in position to maintain the bone segments in fixed spaced relationship to maintain the fracture 131 compressed even after the bone compression device has been removed. Thereafter, the adjustment levers 115 and 117 may be loosened and the arms 65 and 67 raised off the pins 111 and 113 and such pins cut off at the outer surface of the cast 135 to thereby leave the patient free to move about without the cumbersome arms 65 and 67 or pins 111 and 113 projecting from the cast.

The bone compression device shown in FIG. 7 is similar to that shown in FIG. 1 except that it has a pair of downwardly opening bores in each of the arms 65 and 67 for selective receipt of the respective cylindrical blunt ended pins 111 and l 13, one of each of such pairs of bores being through bores to enable the pins 111 and 113 to project upwardly therethrough as shown in FIG. 7. The pins 1 11 and 113 are preferably at least 5 inches long to provide adequate length for engagement on one extremity with the bone and projection from the wounds 159 and 161 a distance sufficient for convenient connection with the arms 65 and 67. A pair of thumb screws 141 and 143 are screwed through transverse threaded bores in the respective arms 65 and 67 to engage and grip the pins 111 and 113 to hold them in their telescoped position within such bores. As shown in FIG. 7 the subject bone compression device may beutilized in a closed reduction operation wherein puncture wounds 151 and 153 are made in the limb flesh 155 above and below the fracture site 157. A bone drill is then inserted in each of the puncture wounds 151 and 153 to drill respective holes 159 and 161 in the fractured bone 156 for receipt of the pins 111 and 113. The pins 111 and 113 may then be inserted and the thumb screws 143 tightened to grip the pins and hold them in their telescoped position in the respective arms 65 and 67. The tightening screws 79 may then be rotated to draw the arms 65 and 67 together to thereby draw the bone segments together and compress the fracture site 157.

The thumb screws 143 may then be released and the respective arms 65 and 67 telescoped upwardly on the respective pins 111 and 113 to the position shown in FIG. 8. A plaster cast 161 may then be applied to the limb'l55 to hold the bone segments in axial alignment and to hold the pins 111 and 113 in fixed spaced relationship to maintain the fracture 157 in compression. Thereafter, the thumb screws 143 may then be loosened and the arms 65 and 67 slid off the pins 111 and 113 and such pins cut off at the surface of the plaster cast 161.

FIG. depicts another operation in which the bone compression device of FIG. 7 may be utilized. In this operation an X-ray is taken of the fractured limb to locate the fracture site and puncture wounds 165 and 167 are made in the flesh 169 and a bone drill inserted in such wounds to drill respective bores 171 and 173 in the bone 175 on opposite sides of the fracture site 177. An incision 181 may then be made directly over the fracture site but at a location on the limb rotated 90 from the puncture wounds 165 and 167 to enable the surgeon to have access to such incision without interference by the bone compression device. The bone 175 may then be stripped at the fracture site and muscle retractors 183 and 185 inserted to retract the muscles from such fracture site. A compression plate 187 may then be placed over the fracture site 177 and while the bone compression device holds such fracture in compression, holes may be drilled for bone screws 189 and such screws inserted to hold the fracture site 177 in compression. The tightening rods 79 may then be loosened and the pins 111 and 113 removed from the bores 171 and 173. The muscle retractors 183 and 185 may then be removed from the incision 181 and the puncture wounds and 167 closed.

The operation shown in FIG. 11 is similar to that shown in FIG. 10 except that the pin receiving bores 201 and 203 are drilled within the incision 181 and are drilled at an angle to one another. In order to accommodate the variation in angularity between the bores 201 and 203, the tightening rods 79 are adjusted to angle the arms 65 and 67 and consequently, the pins 111 and 113, for convenient receipt in the bores. This feature is particularly important in that it does away with the necessity of drilling the bores 201 and 203 exactly parallel to one another. Consequently, there is no requirement for setting up a jig for drilling the bores 201 and 203 exactly parallel to one another or for redrilling such bores until two bores are obtained which are exactly parallel to one another. This capability of accommodating bores which extend at an angle to one another is a particularly important feature when the bone compression device is utilized outside the confines of an operating room such as on a battlefield where it is not so convenient for the surgeon to drill the bores exactly parallel to one another. After the compression plate 211 has been secured to the bone to maintain the fracture 213 in compression, the tightening rods 79 may be loosened and the pins 111 and 113 retracted to enable the incision 181 to be closed.

The bone compression device shown in FIG. 13 is similar to that described above except that a guide 217 is mounted from the arm 65 by means of a screw 219. Such guide is formed with a longitudinal slot 221 which slidably receives a screw 223 projecting from the arm 67 to thereby cooperate with the tightening rods 79 to maintain the arms 65 and 67 projecting parallel to one another. Consequently, the slide 217 will serve to maintain the arms 65 and 67 extending parallel to one another as shown in FIG. 1 for convenient use in conjunction with a compression plate 102. 7

From the foregoing it will be apparent that the bone compression device of present invention provides. a convenient means for use in either an open or closed reduction operation and with or without a compression plate. The subject bone compression device has been employed in a number of operations by both the inventor and others and has enjoyed very favorable reception.

Various modifications and changes maybe made with regard to the foregoing detailed description without departing from the spirit of the invention.

1 claim:

1. A bone compression device comprising:

first and second arms including respective first and second pins on their respective one ends;

tightening means including first and second pairs of fi and Second pling Said first couplings attachment element engaging said pin attachment being formed with retaining means and said element, the opposite extremities of said pin second couplings being formed with threaded means forming holding portions; bores; first and second holding means on said respective pivot means mounting said first pair of couplings in first and second arms and receiving said respective spaced apart relationship on said first arm and said 10 h ldi portions f id i mean id nd second pair of couplings in spaced apart rclationholding means receiving said second holding porp said second and tion telescopically and including releasable adjusta pair of externally threaded tightening rods screwed m means engaging id second h ldi ni mm sald threaded bores and including respective tightening means for interconnecting said arms for securing man's mtatably connected with said drawing said arms together and including at least retaining means whereby Said rods y be rotated first and second couplings pivotally mounted on one diremvion P? Said P f apart a f said first and second arms and first and second second couplings and said second and first arms site, sa d pins inserted in said bores and said rods and operative to draw said arms together while 3 :23: gz zgg sztg' g g 1 2:23;: said pivotal couplings accommodate manipulation to ether mcom re fr t of said arms to extend at different ang les with g p SS Sal ac respect to one another whereby said ad ustment thific l sgzsf p deuce as set t m claim 1 25 means may; be rleleaseddto enable :saicii sgcondtpin means to e te escope to an ex en e posi ion tment means for securin said first in in osii m-the plan? of the up of am filStpm {mans for li dn in said mounting means whereby s id first in insertion of said bone engagmg pqmons m respecp tive bores drilled in a fractured bone on opposite may be removed. and replaced with a different sized pin. a 7 sides of a fracture therein and said tightening 3. A bone compression device as set forth in claim 1 means. nghteneq to compress. sald fracture and althat includes: ternatively, said compression plate may be first and second mounting means for mounting said arlchonfd to said bone on one Side of.sald fractur? first and second pins on said first and second arms adjustment means loosened t? i and respective first and second adjustment means means "t to a retract! posmon with 8am for adjusting the distance which said first and plan: engagmg clement extending short f a.plane second pins project from said respective first and thfough end of the P of second arms 40 said first pin means so said bone erigagrng portion 4. A bone compression device as set forth in claim 1 may be mserted a bore drilled m said P wherin: the side of said fracture opposite said one side, said said first and second arms include respective first and P t ngagi g element engaged with said pin ensecond longitudinal passages telescopically receivgaging fi "ghtenmg means f to ing said respective first and second pins and 5 sad "3 together to compre ss w" releasable adjustment means for holding said pins extrema) of Said P PP 531d f F- in, selected telescopical position in said passages tremlty y be f ed) saidbone on the Sald h b i h l means may be released to of said fracture oppos te said one side to maintain adjust both of said pins to project a selected said fracture compressed after said device is removed therefrom.

distance from said arms 'for receipt in respective first and second elongated pin means formed on their respective one extremities with respective bone engaging portions, said second bone engaging por- I tions having a surface defining a compression plate 8. A bone compression device as set forth in claim 7 v bores drilled in a bone or to adjust said one pin to wherein:

project less than said selected distance from said g first arm for receipt in a b i a compression said tightening means includes apair of spaced apart plate. I 1 couplings mounted on each of said first and second 5. A bone compression device as set forth in claim 1 55 arms, at least one p g of each P being that includes:" 1 formed with respective threaded bores extending guide means interposed between said arms for maint erethrough and a pair of relatively small diametaining said arms parallelto oneanother. ter threaded rods engaged between said couplings, 6. A bone compression device as set forth in claim 1 with each of said rods being engagedwith oneof that includes: I a said threaded bores and including respective enfirst and second tubes mounted on said first and larged in cross section fingergrasp heads.

second arms for telescopical receipt of said respec- 9. A bone .compression device as set forth in claim 8 tive first and second pins. wherein: 7. A bone compression device comprising: said arms are atleast 4 inches long; a compression plate formed on one extremity with a said second pin means is at least 3 inches long.

pin attachment element; 10. A bone compression device as set forth in claim 7 first and second coextensive arms; wherein:

said first and second holding means are formed with and said device includes;

respective first and second pairs of first and second a second pair of pin means selectively received in downwardly opening passages, said fir d said second passages of said first and second pairs second pins means being received in said first of passagespassages of said first and second pairs of passages 

1. A bone compression device comprising: first and second arms including respective first and second pins on their respective one ends; tightening means including first and second pairs of first and second couplings, said first couplings being formed with retaining means and said second couplings being formed with threaded bores; pivot means mounting said first pair of couplings in spaced apart relationship on said first arm and said second pair of couplings in spaced apart relationship on said second arm; and a pair of externally threaded tightening rods screwed into said threaded bores and including respective securing means rotatably connected with said retaining means whereby said rods may be rotated in one direction to space said pins apart a selected distance for insertion in respective bores drilled in a fractured bone on opposite sides of a fracture site, said pins inserted in said bores and said rods rotated in the opposite direction to draw the bone fragments on opposite sides of said fracture together to compress said fracture.
 2. A bone compression device as set forth in claim 1 that includes: mounting means for removably mounting said first pin on said first arm and including releasable adjustment means for securing said first pin in position in said mounting means whereby said first pin may be removed and replaced with a different sized pin.
 3. A bone compression device as set forth in claim 1 that includes: first and second mounting means for mounting said first and second pins on said first and second arms and respective first and second adjustment means for adjusting the distance which said first and second pins project from said respective first and second arms.
 4. A bone compression device as set forth in claim 1 wherein: said first and second arms include respective first and second longitudinal passages telescopically receiving said respective first and second pins and releasable adjustment means for holding said pins in selected telescopical position in said passages whereby said holding means may be released to adjust both of said pins to project a selected distance from said arms for receipt in respective bores drilled in a bone or to adjust said one pin to project less than said selected distance from said first arm for receipt in a bore in a compression plate.
 5. A bone compression device as set forth in claim 1 that includes: guide means interposed between said arms for maintaining said arms parallel to one another.
 6. A bone compression device as set forth in claim 1 that includes: first and second tubes mounted on said first and second arms for telescopical receipt of said respective first and second pins.
 7. A bone compression device comprising: a compression plate formed on one extremity with a pin attachment element; first and second coextensive arms; first and second elongated pin means formed on their respective one extremities with respective bone engaging portions, said second bone engaging portions having a surface defining a compression plate attachment element engaging said pin attachment element, the opposite extremities of said pin means forming holding portions; first and second holding means on said respective first and second arms and receiving said respective holding portions of said pin means, said second holding means receiving said second holding portion telescopically and including releasable adjustment means engaging said second holding portion; tightening means for interconnecting said arms for drawing said arms together and including at least first and second couplings pivotally mounted on said first and second arms and first and second tightening rods engagable between said first and second couplings and said second and first arms and operative to draw said arms together while said pivotal couplings accommodate manipulation of said arms to extend at different angles with respect to one another whereby said adjustment means may be released to enable said second pin means to be telescoped to an extended position with the bone engaging position thereof terminating in the plane of the tip of said first pin means for insertion of said bone engaging portions in respective bores drilled in a fractured bone on opposite sides of a fracture therein and said tightening means tightened to compress said fracture and alternatively, said compression plate may be anchored to said bone on one side of said fracture, said adjustment means loosened, said second pin means retracted to a retracted position with said plate engaging element extending short of a plane through the end of the bone engaging portion of said first pin means so said bone engaging portion may be inserted in a bore drilled in said bone on the side of said fracture opposite said one side, said plate engaging element engaged with said pin engaging element, said tightening means actuated to draw said arms together to compress said fracture so the extremity of said plate opposite said first extremity may be affixed to said bone on the said side of said fracture opposite said one side to maintain said fracture compressed after said device is removed therefrom.
 8. A bone compression device as set forth in claim 7 wherein: said tightening means includes a pair of spaced apart couplings mounted on each of said first and second arms, at least one coupling of each pair being formed with respective threaded bores extending therethrough and a pair of relatively small diameter threaded rods engaged between said couplings, with each of said rods being engaged with one of said threaded bores and including respective enlarged in cross section fingergrasp heads.
 9. A bone compression device as set forth in claim 8 wherein: said arms are at least 4 inches long; said second pin means is at least 3 inches long.
 10. A bone compression device as set forth in claim 7 wherein: said first and second holding means are formed with respective first and second pairs of first and second downwardly opening passages, said first and second pins means being received in said first passages of said first and second pairs of passages and said device includes; a second pair of pin means selectively received in said second passages of said first and second pairs of passages. 